GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seats System Check?

--

Go to Step 2

Go to Lumbar Support System Check

2

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminal C and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 11

3

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminal A and ground.
  3. Set and hold the driver seat lumbar adjuster switch to the AFT position.

Does the test lamp light?

--

Go to Step 4

Go to Step 12

4

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminal F and ground.
  3. Set and hold the driver seat lumbar adjuster switch to the FORE position.

Does the test lamp light?

--

Go to Step 5

Go to Step 15

5

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminal B and ground.
  3. Set and hold the driver seat lumbar adjuster switch to the AFT position.

Does the test lamp light?

--

Go to Step 6

Go to Step 17

6

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminal E and ground.
  3. Set and hold the driver seat lumbar adjuster switch to the FORE position.

Does the test lamp light?

--

Go to Step 7

Go to Step 17

7

  1. Connect a test lamp.
  2. Backprobe between the fore/aft lumbar adjuster relay connector terminals C and D.

Does the test lamp light?

--

Go to Step 8

Go to Step 18

8

Inspect for a poor connection or open in CKTs 610 or 611.

Did you find a poor connection or open in CKTs 610 or 611?

--

Go to Step 9

Go to Step 10

9

  1. Repair the poor connection or open in CKTs 610 or 611.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

10

  1. Replace the fore/aft lumbar adjuster relay.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

11

  1. Repair the poor connection or open in CKT 340 between S331 and the fore/aft lumbar adjuster relay connector terminal C.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

12

Inspect for a poor connection or open in CKT 466.

Did you find a poor connection or open in CKT 466?

--

Go to Step 13

Go to Step 14

13

  1. Repair the poor connection or open in CKT 466.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

14

  1. Replace the driver seat lumbar adjuster switch.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

15

Inspect for a poor connection or open in CKT 385.

Did you find a poor connection or open in CKT 385?

--

Go to Step 16

Go to Step 14

16

  1. Repair the poor connection or open in CKT 385.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

17

  1. Replace the fore/aft lumbar support motor. Refer to Front Seat Lumbar Support Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK

18

  1. Repair the poor connection or open in CKT 750 between S330 and the fore/aft lumbar adjuster relay.
  2. Inspect the system.

Is the repair complete?

--

Go to Lumbar Support System Check

System OK